1. Field of the Invention
This invention relates to structural repair methods. More specifically, the invention is a method and system for repairing cracks found in structures.
2. Description of the Related Art
The root cause of metallic-structural fatigue failure is the initiation and propagation of cracks. Typically, cracks start at local regions of high stress (e.g., bolt holes, corners, etc.) or at microscopic defects inherent in the material (e.g., voids, particles, etc.). To assure that structures (e.g., buildings, bridges, airplanes, aerospace vehicles, etc.) remain operationally safe, routine crack inspection and crack repair programs are utilized. These programs typically consist of the following steps:                determining a safe level of crack damage based on fracture mechanics concepts;        inspecting a structure to insure that the damage state is acceptable; and        repairing the structure before the crack damage exceeds safe levels.        
Current research in this field has focused on refining the criteria that defines safe crack levels and improving damage monitoring methods/systems (i.e., a field that has come to be known as “structural health monitoring”). However, when it comes to repairing cracks in structures, the approaches vary widely and are generally industry specific, thereby leading to varying degrees of confidence in crack repairs.